/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.sun.jini.phoenix;
import java.security.Permission;
import java.io.FilePermission;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
/**
* Represents permission to use a specific option or options in the command
* for creating an activation group. An instance of this class contains a
* name (also referred to as a "target name") but no actions list; you either
* have the named permission or you don't. The target name can be any of the
* following forms:
* <pre>
* "<i>literal</i>"
* <i>literal</i>*
* <i>literal</i>{<i>fpname</i>}
* <i>string</i>
* </pre>
* A target name is parsed according to the first form (in the order given
* above) that it matches. A <i>literal</i> is zero or more arbitrary
* characters. An <i>fpname</i> is zero or more characters, none of which
* are '{'. A <i>string</i> is zero or more arbitrary characters that do
* not match any of the previous forms.
* <p>
* An option <i>option</i> matches a target name of the form
* "<i>literal</i>" if <i>option</i> is equal to <i>literal</i>.
* <p>
* An option <i>option</i> matches a target name of the form
* <i>literal</i>* if <i>option</i> starts with <i>literal</i>.
* <p>
* An option <i>option</i> matches a target name of the form
* <i>literal</i>{<i>fpname</i>} if <i>option</i> starts with
* <i>literal</i> and the remainder of <i>option</i> matches <i>fpname</i>
* according to the matching semantics defined by {@link FilePermission};
* that is, if a <code>FilePermission</code> created with target name
* <i>fpname</i> (and some actions) implies a <code>FilePermission</code>
* created with the remainder of <i>option</i> (and the same actions).
* <p>
* An option <i>option</i> matches a target name of the form
* <i>string</i> if <i>option</i> is equal to <i>string</i>.
*
* @author Sun Microsystems, Inc.
*
* @since 2.0
*/
public final class ExecOptionPermission extends Permission {
private static final long serialVersionUID = 5842294756823092756L;
/**
* the name without any wildcard or fpname on the end
*/
private transient String prefix;
/**
* true if the name ended with a wildcard or fpname, false otherwise
*/
private transient boolean plain;
/*
* FilePermission containing fpname, if any
*/
private transient Permission fp;
/**
* Constructs an instance with the specified name.
*
* @param name the target name
* @throws NullPointerException if the name is <code>null</code>
*/
public ExecOptionPermission(String name) {
super(name);
if (name == null) {
throw new NullPointerException("name cannot be null");
}
init(name);
}
/**
* Parses the target name and initializes the transient fields.
*/
private void init(String name) {
prefix = name;
plain = true;
int last = name.length() - 1;
if (last >= 0) {
char c = name.charAt(last);
if (c == '"' && last > 0 && name.charAt(0) == '"') {
prefix = name.substring(1, last);
} else if (c == '*') {
prefix = name.substring(0, last);
plain = false;
} else if (c == '}') {
int mid = name.lastIndexOf('{');
if (mid >= 0) {
prefix = name.substring(0, mid);
String fpname = name.substring(mid + 1, last);
if (!fpname.equals("<<ALL FILES>>")) {
fp = new FilePermission(fpname, "read");
}
plain = false;
}
}
}
}
/**
* Returns <code>true</code> if the specified permission is an instance
* of <code>ExecOptionPermission</code> and every option that matches
* the name of specified permission also matches the name of this
* permission; returns <code>false</code> otherwise.
*
* @param p the permission to check
* @return <code>true</code> if the specified permission is an instance
* of <code>ExecOptionPermission</code> and every option that matches
* the name of specified permission also matches the name of this
* permission; <code>false</code> otherwise
*/
public boolean implies(Permission p) {
if (!(p instanceof ExecOptionPermission)) {
return false;
}
ExecOptionPermission ep = (ExecOptionPermission) p;
if (plain) {
return ep.plain && prefix.equals(ep.prefix);
} else if (fp == null) {
return ep.prefix.startsWith(prefix);
} else if (ep.plain) {
return (ep.prefix.startsWith(prefix) &&
fp.implies(new FilePermission(
ep.prefix.substring(prefix.length()),
"read")));
} else {
return prefix.equals(ep.prefix) && fp.implies(ep.fp);
}
}
/**
* Two instances of this class are equal if each implies the other;
* that is, every option that matches the name of one instance matches
* the name of the other instance.
*/
public boolean equals(Object obj) {
if (!(obj instanceof ExecOptionPermission)) {
return false;
}
ExecOptionPermission p = (ExecOptionPermission) obj;
return (prefix.equals(p.prefix) &&
plain == p.plain &&
(fp == null ? p.fp == null : fp.equals(p.fp)));
}
/**
* Returns a hash code value for this object.
*/
public int hashCode() {
int h = prefix.hashCode();
if (!plain) {
if (fp != null) {
h += fp.hashCode();
} else {
h++;
}
}
return h;
}
/**
* Returns the empty string.
*/
public String getActions() {
return "";
}
/**
* Recreates any transient state.
*
* @throws InvalidObjectException if the target name is <code>null</code>
*/
private void readObject(ObjectInputStream s)
throws IOException, ClassNotFoundException
{
s.defaultReadObject();
if (getName() == null) {
throw new InvalidObjectException("name cannot be null");
}
init(getName());
}
}